Petrolatum (petroleum), oxidized, Bu ester

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 March 2013 to 5 April 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, conducted to a valid guideline and was performed under GLP conditions.

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: LAB-ÁLL Bt. Budapest, 1174 Hunyadi u. 7.
- Weight at study initiation: 330 - 360 g (males); 331 - 360 g (females)
- Housing: animals were housed in macrolon cages, sive V., with 5 animals per cage
- Diet: CuniFort Intensive Rabbit Diet Mixture (Tendre Ltd., 2942 Nagyigmánd, Hungary) ad libitum
- Water: tap water, ad libitum containing 50 mg/100 mL ascorbic acid
- Acclimation period: 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light

Route:

epicutaneous, occlusive

Vehicle:

other: oleum helianthi

Concentration / amount:

The test material was applied unchanged (undiluted) during induction exposure; control animals were exposed to vehicle. For challenge exposure, all treatment and control animals were exposed to test material at a concentration of 50 % (w/v).

Route:

epicutaneous, occlusive

Vehicle:

other: oleum helianthi

Concentration / amount:

The test material was applied unchanged (undiluted) during induction exposure; control animals were exposed to vehicle. For challenge exposure, all treatment and control animals were exposed to test material at a concentration of 50 % (w/v).

No. of animals per dose:

20 animals (per treatment group); 10 animals (per control group)

Details on study design:

RANGE FINDING TESTS
Test material was evaluated at concentrations of 25, 50, 75 and 100 % prepared w/v in vehicle to two animals. Occlusive exposure was for 6 hours with 0.5 mL formulation administered per animal.
It was found that application of test formulation at concentrations of 25 and 50 % (w/v) produced no reaction on the skin of the guinea pigs. At a concentration of 75% (w/v) one animal was found to have very slight erythema at the application site one hour after patch removal. Both animals administered test material in its undiluted state were found to have slight erythema at the application site one hour after patch removal. As a result of preliminary experiments, test material was used in undiluted state for dermal induction treatments and at concentration of 50 % (w/v) for challenge treatment.

MAIN STUDY
A. INDUCTION EXPOSURE (Day 0)
The right flank area of all animals was clipped free of fur 24 hours prior to treatment. A 5 x 5 cm patch of sterile gauze patch was saturated with the test material in undiluted state and covered the right sides of animals. The patch was occluded and fastened with an adhesive hypoallergenic plaster. Control animals were treated with 0.5 mL vehicle, using similar treatment procedures as in test groups. The duration of exposure was 6 hours. After patch removal any remaining test material was removed with a gauze swab and water at body temperature.

B. INDUCTION EXPOSURE (Days 7 and 14)
The same application as on day 0 was carried out on the same test area (cleared of hair if necessary) of the same flank on day 7, and again on day 14.
Following the dermal induction treatment the animals were left untreated for 14 days prior to challenge.

C. CHALLENGE EXPOSURE
Two weeks after induction, the shawn left flanks of the animals (both the test and control) were treated with 0.5 mL of 50 % (w/v) test material formulation. The right shaved flanks were treated with 0.5 mL of vehicle. Following patch removal (after 6 hours), any residual test material was removed with a gauze swab and water at body temperature.

EXAMINATIONS
- Mortality: checks for mortality were performed daily from delivery of the animals to study termination
- Clinical signs: recorded daily for each animals during the test
- Bodyweight: individual body weights were recorded at the beginning and at the end of experiments
- Skin reaction: skin reactions were recorded during induction exposure 1, 24, 48 and 72 hours after patch removal. Skin reactions were evaluated according to the scoring system of Draize (1959) (See table 2).
Skin reaction were recorded during challenge exposure 24 and 48 hours after patch removal. The first scoring was performed 30 hours post applications (24 hour value). The second grading was carried out the day after (48 h values). Classification and scoring was done according to the system outlined in table 3.

DATA EVALUATION
To classify the sensitisation responses the primary irritation of the test material was taken into consideration. The percentage of animals showing positive reaction was calculated in both (test and control) groups. As a result of these, the percentage value of the control animals that responded were subtracted from the percentage of the test animals responded positively to the challenge. The net response value resulted the sensitisation rate in percent.

According to the Regulation (EC) No 1272/2008 if at least 15 % of the animals show allergic response, after the Buehler procedure, the test material should be classified as a "sensitiser".

Challenge controls:

Naive animals which were dosed with the vehicle during the induction phases were treated with the test material at the challenge exposure at a concentration of 50 %.

Positive control substance(s):

yes

Remarks:

2-mercaptobenzothiazole

Positive control results:

The sensitivity and reliability of the experimental procedure is assessed at the test laboratory twice a year by use of items which are known to have moderate skin sensitisation properties, such as 2-mercaptobenzothiazole.
During the reliability check, 20 test group animals were treated with 2-mercaptobenzothiazole at 75 % (w/v) in 1 % methyl cellulose during induction exposure, and at 50 % (w/v) in 1 % methyl cellulose during challenge exposure. A positive response was seen in 9 out of the 20 animals treated. 10 control animals were included in the test; they were treated with vehicle only. No signs of skin reaction were noted in control animals.
2-mercaptobenzothiazole was therefore found to evoke a positive response in the reliability check, thereby confirming the reliability of the test method used.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Induction: Undiluted; Challenge: 50 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No visible change

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: Induction: Undiluted; Challenge: 50 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No visible change.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: Undiluted; Challenge: 50 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No visible change

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: Induction: Undiluted; Challenge: 50 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No visible change.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

Induction: Vehicle only; Challenge: 50 %

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No visible change

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: Induction: Vehicle only; Challenge: 50 %. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No visible change.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

Induction: Vehicle only; Challenge: 50 %

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No visible change

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: Induction: Vehicle only; Challenge: 50 %. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No visible change.

Main Study

- Test group

A group of 20 animals was treated with the test item during the induction phases of the study. The animals were challenged by dermal exposure two weeks later.

 

After the challenge with the test material at a concentration of 50 % no positive response was observed in any of the animals of the test group. The mean of the scores was 0.00 according to the 24 and 48-hour results. On the opposite (right) side treated with vehicle no reaction was found.

 

- Control group

Ten control animals were exposed to vehicle during the induction phases of the study. The animals were treated with the test material on the challenge day only.

No visible changes were found at the 24 and 48 hour examinations. During the challenge exposure, the test material, at a concentration of 50 % w/v, did not evoke primary irritation. 

 

Body Weight

There were no notable differences between the test animal group and the control group.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Challenge with test material at a concentration of 50 % (w/w) evoked no positive response in test animals. At the same time, no positive response was noted in animals of the control group. The net response value represented an incidence rate of 0 % and the net score value of 0.00. Therefore, the results indicate that the test material is non-sensitising to guinea pigs under the conditions of this study.

Executive summary:

The potential for the test material to cause skin sensitisation was investigated in a GLP study which was conducted according to the standardised guidelines OECD 406, EU Method B.6 and EPA OPPTS 870.2600, following the Buehler method. During the study 20 test animals were subjected to sensitisation procedures in three topical applications. The test material was used in an undiluted state for dermal sensitisation treatments. Two weeks following the last induction exposure, a challenge dose was administered. Challenge was performed by dermal application of the test item at concentration of 50 % (w/v). 10 control guinea pigs were simultaneously exposed to vehicle during the sensitisation phase and they were treated with the test material (at a concentration of 50 %) only at the challenge phase.

 

No signs of contact sensitisation were detected in guinea pigs exposed previously to the test material during experiments. In the control and treated animals the mean of the scores was 0.00 according to the 24 and 48-hour results. Therefore, the results indicate that the test material is non-sensitising to guinea pigs under the conditions of this study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The potential for the test material to cause skin sensitisation was investigated in a GLP study which was conducted according to the standardised guidelines OECD 406, EU Method B.6 and EPA OPPTS 870.2600, following the Buehler method. During the study 20 test animals were subjected to sensitisation procedures in three topical applications. The test material was used in an undiluted state for dermal sensitisation treatments. Two weeks following the last induction exposure, a challenge dose was administered. Challenge was performed by dermal application of the test item at concentration of 50 % (w/v). 10 control guinea pigs were simultaneously exposed to vehicle during the sensitisation phase and they were treated with the test material (at a concentration of 50 %) only at the challenge phase.

 

No signs of contact sensitisation were detected in guinea pigs exposed previously to the test material during experiments. In the control and treated animals the mean of the scores was 0.00 according to the 24 and 48-hour results. Therefore, the results indicate that the test material is non-sensitising to guinea pigs under the conditions of this study.

The study was performed under GLP conditions and an accepted standardised guideline with a high level of reporting. The study was therefore assigned a reliability score of 1 according to the criteria of Klimisch (1997).

Migrated from Short description of key information:
Not sensitising, male/female guinea pig, OECD 406, EU Method B.6, EPA OPPTS 870.2600 (Buehler method), Stáhl (2013)

Justification for selection of skin sensitisation endpoint:
Only one study is available.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In accordance with the criteria for classification and labelling as defined in Regulation (EC) No 1272/2008 (CLP) and Directive 67/548/EEC (DSD), the substance does not require classification for skin sensitisation.